Genetic Diversity and Structure of an Endangered Medicinal Plant Species in the Northern Balruk Mountains: Implications for Conservation.

Background: Fritillaria karelinii is an endangered medicinal herb mainly distributed in Central Asia, extending to northwestern China. Due to habitat fragmentation, overharvesting, and poor natural regeneration, this species has been designated as a Grade II national key protected species in China. Methods: To inform effective conservation strategies, we assessed the genetic diversity and population structure of F. karelinii using single nucleotide polymorphism (SNP) loci obtained via genotype-by-sequencing (GBS). A total of 87 individuals from 11 sampling sites across the Tacheng region in northern Xinjiang were genotyped, representing the species' known extant distribution in China. Results: A relatively high level of genetic diversity (mean HE = 0.1461) was detected in the species, and Bayesian assignment divided the sampled populations into two subtle but detectable genetic clusters. Conclusions: The relatively high diversity may be attributed to the edge-population effect and long-lived life-history traits, while the weak differentiation between the two groups may reflect restricted gene flow and genetic drift resulting from habitat isolation. Based on these findings, we propose conservation actions including immediate fencing of habitats to exclude livestock, ex situ germplasm collection separately from the two genetic groups as distinct management units, and cautious evaluation of potential germplasm introduction from Central Asia to broaden the genetic base while preserving local adaptation.